There are certain circumstances where welding operations must be done in the field instead of in a workplace (at the bench). For example, when heavy machinery breaks during use, it is often infeasible or uneconomical to move the machinery to a workplace where it can be repaired. Instead, the machinery must be repaired in situ.
Prior art systems for providing field welding have a number of disadvantages in performance, economics, timeliness, reliability, noise, safety, repairability, complexity, and ease of use. One prior art attempt for field welding is the use of a generator welder or a heavy and cumbersome portable welder. A traditional portable welder may be powered in a number of ways. One method requires such a portable welder to be dependently plugged in to a utility supplied power grid via a very long drop cord. This severely limits the applicability of such a system to where utility power is available because the range of a drop cord is limited. In addition, a drop cord can short out, creating a fire hazard. In many cases, there is no power grid resource available in the location where use is required.
Prior art portable Gen-Set systems start by implementing 60 cycles alternating current (AC) electrical power, typically at 240 volts, single or three phase AC; designed on a derivation of integrated circuits (IC's) configured to regulate welder output. Heating and vibration are harmful to typical circuit elements and IC's; compounded when driven by an internal combustion engine as entropy increases rapidly inside such a system as heat exponentially increases at higher current levels. Typical portable welders deliver a narrow spectrum of low quality output power and a poor usable duty cycle at the expense of waste heat. Most Gen-Set portable welder power sources are large and heavy and will overheat while delivering, noisy noxious exhaust gases, a derated duty cycle, high consumables such as MIG/TIG components and gases. The result is a cumbersome, unpredictable, and unreliable welder output of derated performance, all at a very high cost.